| A | B |
|---|
| nucleus | dense, positively charged mass located in the center of the atom |
| proton | positively charged subatomic particle that is found in the nucleus of an atom |
| electron | negatively charged subatomic particle that is found in the space outside the nucleus |
| neutron | neutral subatomic particle that is found in the nucleus of an atom |
| atomic number | number of protons in an atom of an element |
| mass number | sum of the protons and neutrons in an atom of an element |
| isotopes | atoms of the same element that have different numbers of neutrons and different mass numbers |
| energy levels | possible energies that electrons in an atom can have |
| electron cloud | a visual model of the probable locations of electrons in an atom |
| orbital | region of space around the nucleus where an electron is likely to be found |
| electron configuration | arrangement of electrons in the orbitals of an atom |
| ground state | all the electrons in an atom have the lowest possible energies |
| continuous theory of matter | no limit to number of times matter can be divided |
| discontinuous theory of matter | matter made of extremely small particles that could not be divided |
| Aristotle's Theory of Matter | continuous theory of matter |
| Democritus' Theory of Matter | discontinuous theory of matter |
| John Dalton | applied experimental methods to idea of atom |
| Dalton's 1st Postulate | All elements are composed of atoms |
| Dalton's 2nd Postulate | Atoms of the same element have the same mass |
| Dalton's 3rd Postulate | Atoms of different elements have different masses |
| Dalton's 4th Postulate | Compounds contain atoms of more than one element |
| Dalton's 5th Postulate | In a particular compound, atoms of different elements always combine in the same way |
| Plum Pudding Model of Atom | negative charges scattered in positive mass of matter |
| Thompson Model of Atom | Plum Pudding Model |
| Rutherford Atomic Experiment | bombarded gold foil with alpha particles |
| Nuclear Model of Atom | mass of atom in small central area, most of atom empty space |
| Rutherford Model of Atom | Nuclear Model |
| Energy Level Model of Atom | electrons move in fixed orbits around nucleus corresponding to their specific energy |
| Bohr Model of Atom | Energy Level Model |
| line spectra | unique set of light wavelengths released by excited substance returning to ground state |
| Aufbau Principle | electrons occupy the orbitals of lowest energy first |
| Pauli Exclusion Principle | orbital can only hold 2 electrons with opposite spin |
| Hund's Rule | electrons will not double up until each orbital has at least 1 electron |
| Heisenberg Uncertainty Principle | position and momentum of electron CANNOT be determined at the same time |
| Principle Quantum Number | describes energy levels |
| n | represents the Principle quantum number |
| Second Quantum Number | describes energy sublevels |
| l | Second Quantum Number |
| sharp sublevel | "s" energy sublevel |
| "s" sublevel | first energy sublevel |
| principal sublevel | "p" energy sublevel |
| "p" energy sublevel | second energy sublevel |
| diffuse sublevel | "d" energy sublevel |
| "d" energy sublevel | third energy sublevel |
| fundamental energy sublevel | "f" energy sublevel |
| "f" energy sublevel | fourth energy sublevel |
| Third Quantum Number | describes the orbitals in sublevel |
| ml | Third Quantum Number |
| Fourth Quantum Number | describes spin |
| ms | Fourth Quantum Number |
| Louis de Broglie | electron can act like a wave or a particle |
| James Chadwick | confirms existence of neutron |
| Erwin Shrodinger | equations describing electron motions |
| configuration of H | 1s1 |
| configuration of He | 1s2 |
| configuration of Li | 1s22s1 |
| configuration of Be | 1s22s2 |
| configuration of B | 1s22s22p1 |
| configuration of C | 1s22s22p2 |
| configuration of N | 1s22s22p3 |
| configuration of O | 1s22s22p4 |
| configuration of F | 1s22s22p5 |
| configuration of Ne | 1s22s22p6 |
| configuration of Na | 1s22s22p63s1 |
| configuration of Mg | 1s22s22p63s2 |
| configuration of Al | 1s22s22p33s23p1 |
| configuration of Si | 1s22s22p33s23p2 |
| configuration of P | 1s22s22p63s23p3 |
| configuration of S | 1s22s22p63s23p4 |
| configuration of Cl | 1s22s22p63s23p5 |
| configuration of Ar | 1s22s22p63s23p6 |
